1. Field of the Invention
This invention relates generally to a fastener of the type which may be used to secure a number of apertured or slotted members together. More specifically, the invention relates to a fastener for securing an apertured member to a slotted member which, electively, may be inserted in either a permanent or reusable position, and which will retain its rotational position with respect to the members regardless of any external shocks or vibration that are imparted thereto.
2. Description of the Prior Art
A wide range of fasteners exist for securing members of different thicknesses to one another. One class of known fasteners include an elongate shank and a number of axially spaced apart wing elements along the shank which engage the members when inserted into apertures in the panels. Such fasteners are used widely throughout the automobile fabrication industry and elsewhere to join body panels and the like to other elements in an inexpensive, economical manner.
Recently, in an effort to reduce the required tolerances necessary for the process of fabricating component members and securing the members together, it has become common to use slots for the apertures in one or both of the members. By using slots rather than circular-type apertures, the tolerances to which the members and the overall assembly needs to be manufactured to can be reduced. However, the slots present problems for conventional fasteners, which, largely speaking, were designed for use with circular apertures.
FIGS. 1-3 are a bottom plan view of a prior art connector of the type which is described in U.S. Pat. No. 4,396,329, which issued Aug. 2, 1983 to the present inventor. The fastener 10 is shown in use with a slot 16 which is defined by a first slot edge 12 and a second slot edge 14 in a panel member or the like. Fastener 10 includes a plurality of fins 18 which are arranged in four separate rows that are spaced about its periphery. In FIG. 1, fastener 10 is shown in a first rotational position with respect to slot 16, wherein engagement areas 20 on each of the fins 18 contact the respective edges 12, 14 in order to retain fastener 10 within slot 16. The fastener 10 is usually initially inserted in this position.
As vibrations or shocks are imparted to fastener 10 and the members which are joined therewith, the fastener 10 is likely to rotate to the position illustrated by FIG. 2. In FIG. 2, fastener 10 is secured within slot 16 by only two of the fins 18, through engagement areas 22. Eventually, the fastener 10 may rotate to a position illustrated in FIG. 3, wherein none of the fins 18 are engaged with the slot 16 and the fastener 10. At this point, fastener 10 is no longer secured to the member in which slot 16 is defined, and the connection has failed.
Referring now to FIG. 4, a second type of prior art fastener 24 includes a plurality of circular fins 25, each of which extend around the periphery of the shank of the fastener 24. This type of fastener requires no particular initial orientation to ensure contact of its engagement portions 26 with slot 16, but is manufactured only as a sloped tooth fastener that is non-reusable.
Depicted in FIGS. 5 and 6 is a third type of fastener 28 which includes a pair of semi-circular fins 30 that, when properly oriented with respect to a slot 16, engage the walls of slot 16 at engagement areas 32. However, when fastener 28 is rotated by vibration or shock to the position depicted in FIG. 6, the presence of recess, 33 between the fins 30 results in a smaller engagement area 34 to be in contact with the walls 12, 14 which define the slot.
It becomes evident from the foregoing discussion of previously known connectors that there has existed a long and unfilled need in the prior art for a fastener design for use in slotted panels that provides more positive engagement, a larger area of engagement and that will not rotate once assembled.